Politically speaking, this has been true for some time — a reality largely due to a massive shift in public opinion on the issue, which occurred in late 2011 and accelerated over the intervening years. Here's The Post's trend data on the question of whether gay people should be able to marry:

The trend line in the charts above is pretty clear. But even those charts undersell the steady march of public opinion toward acceptance of legalization of gay marriage. The other key factor to consider in understanding that movement is that young people are far more supportive of legalizing gay marriage than older citizens. Age is actually a more telling indicator of where you stand on gay marriage than party affiliation; more than six in ten Republicans ages 18-29 supported gay marriage in a March Pew poll as compared with just 22 percent of Republicans 65 and older.

But wait, there's more. For people who say that young people who are supportive of gay marriage will change their tune as they age, that is not born out in the data, either. In fact, every generation — including the 65+ group — is growing more okay with gay marriage as they age.

Now, all of these charts make a very clear political argument: The country is rapidly growing more accepting of gay marriage and it seems — given the generational and inter-generational changes in the numbers — very unlikely that that trend will reverse itself. That's a simple political fact that Republican strategists have been trying to drill into the heads of their candidates in recent years; spending significant (or really, any) time talking about opposition to same-sex marriage is a straight political loser with virtually all voters not in the social conservative wing of the GOP base. (Sidebar: That's an amazing transformation in the politics of gay marriage; a decade ago, George W. Bush's reelection victory was credited in no small part to a number of ballot initiatives banning gay marriage on the ballot in key swing states. In 2004, 60 percent of Americans opposed gay marriage while 31 percent supported it, according to Pew.)

The cultural acceptance of gay marriage is something else entirely — and that sort of broader cultural perception is what is probably keeping the nation's highest court away from issuing any sort of wide-reaching ruling at the moment. Consider that even as polling has shown acceptance of same-sex marriage shooting skyward, there has been much less movement on the more ethical/cultural questions related to it. In a Pew poll conducted in June 2013, 45 percent of respondents said it was a "sin" to engage in homosexual behavior, and 45 percent said it was not. That's somewhat remarkable, given that the same poll showed that more than seven in ten people believe that recognition of the legality of same-sex marriage is "inevitable."

The court's ruling (or lack thereof) is expected to extend gay marriage to 30 states — and it's easy to imagine that a number of other states will follow suit in seeking legalization since there will be no pending legislation in front of the court to keep them from doing so. Will there eventually be a challenge to the legality of same-sex marriage in front of the Supreme Court? Yes. Does the makeup of the court make some difference in how that decision turns out? Also, yes. But by not acting on the current challenges, the court has allowed the massive momentum in favor of gay marriage to continue. And not just to continue, but to grow.